Small Joint Fusion Plate and Cutting Block

ABSTRACT

A method and one or more devices for a capitolunate fusion includes a cutting block for attaching to the capitate bone and for cutting the capitate and lunate bones to fit a corresponding plate. The cutting block is removed and a fusion plate is fixed to the capitate and lunate bone with the plate having a capitate section and a lunate section with the capitate section and lunate section of the plate in a generally perpendicular arrangement to allow optimal fusion of the capitate and lunate bones. Further devices include a three and four bone fusion cutting block and fusion plate.

RELATED APPLICATION

This application is a continuation application of, and claims priorityto, U.S. patent application Ser. No. 15/654,682, filed on Jul. 19, 2017which claims priority to U.S. Provisional Patent Application 62/364,288filed on Jul. 19, 2016, both entitled “SMALL JOINT FUSION PLATE ANDCUTTING BLOCK”, the entirety of both are incorporated herein.

FIELD OF THE INVENTION

The present invention related to a method and devices for a surgicalimplant for aligning bones for fusion. Specifically, the presentinvention is ideally suited for aligning and fusing wrist bones throughuse of a surgical bone cutting block and corresponding bone plate.

BACKGROUND

Arthritis, a common problem with many people, is a wearing or loss ofthe cartilage at any joint. The wearing or thinning cartilage can leadto inflammation, pain, loss of motion, and deformity. Arthritis canaffect any joint including the wrist joint which contains numerous bonescalled carpal bones (as seen in FIG. 1). Fusing joint is a commonorthopaedic surgical solution used to address arthritis and jointinstability. In the wrist, there are two common forms of arthritis namedspecifically scaphoid nonunion advanced collapse (SNAC) and scaphoidlunate advanced collapse (SLAC). These types of arthritis result in apredictable progression of arthritis that involves the carpal bones ofthe wrist. One surgical procedure to address the arthritis is to performa scaphoid excision and limited intercarpal fusion. Currently the mostcommon form of intercarpal fusion involves fusion of thelunate-capitate-hamate-triquetral carpal bones. This is also referred toas the four-corner fusion. The four corner fusion fuses together thefour carpal bones by various fusion or fixation methods or techniques.These fixation techniques include K-wires, headless screws, circularplates, and memory staples.

The problem with K-wires is they are unable to provide compressionacross the fusion plane, have limited fixation strength, are less rigid,and can lead to pin tract infections which can often result in earlyremoval. Compression across a fusion plane is beneficial as it increasesfusion rate and time to fusion. In addition, they often lead tosecondary surgical procedures to remove the K-wires if they were buriedduring the index procedure.

Headless screws are technically challenging to use, usually provide lessoptimal compression across the fusion plane, and can lead to ulnarcutaneous nerve injuries. Further, when using a capitolunate headlessscrew one must choose the antegrade or retrograde position. In order tothe insert the screw antegrade, one has to penetrate and create a holdin healthy viable cartilage of the lunate bone. Furthermore, theretrograde option is technically difficult, suboptimal in terms of screwpurchase into the lunate, and the compression across the fusion plane isnot perpendicular.

As seen in FIG. 2A, circular plates 21 have been used to assist in thefour-corner fusion. The problem with the rather large circular plates 21include: (1) nonunion or loose hardware; (2) hardware impingement; (3)post-operative pain; (4) low patient satisfaction; (5) limited pain-freepatients; and (6) the plate alignment and installation procedure aretechnically difficult to achieve consistent success. The two mostsignificant of these complications is the nonunion rate and hardwareimpingement. Reasons for the nonunion include the fact that thesecircular plates have limited ability to compress across the fusionplanes. Further, although the current circular plate systems aredesigned to create a depression on the dorsal carpal bones through areaming process, the plate must still partially rest on the dorsallunate. This part of the dorsal lunate normally articulates with thedorsal distal radius at the upper ranges of wrist extension. Thus, theseplates are prone to inherently impinge against the dorsal radius causingpain, decreased pain satisfaction, and at times necessitating plateremoval.

As seen in FIG. 2B, memory stapes 22 provide an alternative to thecircular plates or K-wires. Staples are also known to have inherentproblems. Staples 22 can be difficult to insert and immediately startcompressing when they touch the bone or when they are released from theinserting tool. Some staples require a secondary heating process tocompress the staples which can cause bone necrosis and decrease fusionrates. Further, the tines on the staples do not provide a rigid fixationlike screws, the staples can back out of the bone and they are not asstrong as titanium (yield strength of 690 Mpa vs. 1000 Mpa for screws).

When attempting to fuse two bones, forcing compression of the bonesagainst each other is a critical factor that determines if the boneswill fuse or not. Ideally, one wants the compression force to be asperpendicular to the bone surfaces being fused. An additional problemwith staples is that compression across the fusion is non-linear as thecompression is greater at the end of the staples and less at the bridge.The force vector of the compression is therefore not perpendicular tothe fusion

In addition to four corner fusions for wrist arthritis, two other formsof intercarpal fusion options exist. Three bone fusions consist offusing the lunate, capitate, and hamate. Two bone fusion consists offusing the lunate and capitate. With these two options, the triquetrumcan either be removed or left in place but just not part of the fusion.In order to perform these two types of fusions, current techniques usesimilar constructs of K-wires, headless screws, or staples as describedabove for four corner fusions. There are no specific circular platesdesigned for two or three bone fusions.

In all three fusion options (2, 3, or 4 bone), the lunate needs to befused with the capitate. The problem with performing a capitolunatefusion with screws is that the bones are very co-linear and there is nota good way to insert a screw across the fusion plane. Further, sinceideal fusion stems from compression perpendicular to the fusion plane,access to and alignment of the perpendicular axis of the fusion plane isa significant challenge. When using a plate construct to fuse the lunateto the capitate, prominent dorsal hardware on the lunate presents aconcern and the technique is difficult to reproduce.

Screw fixation of capitolunate can provide greater linear compressionand more rigid fixation than stapes. However, inserting these screws canbe a technical challenge for surgeons into these two carpal bones due totheir size, shape and location. Two current techniques in insertingthese screws freehand include: (1) antegrade; and (2) retrograde. Bothtechniques are difficult to perform, not ideal in angle or purchase ofthe bone, and not easily reproducible.

Unfortunately, screws are also not an optimal solution as a stand-alonedevice or method for capitolunate fusions. As seen in FIGS. 3A and 3B,the screw or screws 31, 32 are inserted into the main part of thecapitate and lunate bones to provide optimal fusion. However, as seen inFIG. 4, the alignment 41 of the capitate and lunate bones relative toeach other is difficult to obtain an optimal insertion procedure. In theantegrade method (see FIG. 3A), screw 31 insertion requires significantrelease to allow hyperflexion of the wrist. The procedure also leavesholes in good lunate cartilage. Sometimes, proximal screw prominencefrom migration or settling can be a problem causing damage to distalradius cartilage damage and requiring a second surgery to remove thescrew. In the retrograde method (see FIG. 3B), the dorsal capitatetechnique is used which is technically difficult for surgeons to performas the screw 32 insertion is not perpendicular to the fusion plate, itdoes not provide optimal lunate purchase, requires an intercarpaltechnique, is more difficult than the antegrade procedure, can lead toneurovascular injury; and can cause damage to carpometacarpal joints.

When placing a screw antegrade from the lunate to the capitate, twochallenges are encountered. First, in order to get a screw asperpendicular to a standard fusion plane which would be the bestcompression and rigid fixation, one needs to perform significant releaseof the wrist joint in order to achieve extreme wrist flexion. In manypatients with wrist arthritis, they already have significant wristcontractures making achieving this wrist flexion even more difficult.Secondly, in order to get this perpendicular path across the fusionplane, one has to drill and make a hole in the lunate cartilage. Again,this is not ideal as after the procedure the “new” wrist joint will bewholly comprised on this radio-lunate articulation.

Placing the screw in a retrograde fashion would avoid this last issue.However, because of the anatomic relationship of thelunate-capitate-third metacarpal, insertion of the screw is verydifficult. These bones are co-linear and tightly bond. There is no edgeor location that allows a screw to be inserted that is perpendicular tothe fusion. Currently, surgeons utilizing this technique will usuallyplace the screw(s) somewhat oblique to the fusion.

Therefore, what is needed is a new technique and device or devicesenabling use of a screw to fuse the capitate and lunate bones which isgenerally perpendicular to the fusion plane. Ideally the device wouldnot rest on the dorsal surface of the lunate so it wouldn't impinge onthe distal radius. Variation of the device should allow for performing a2, 3, or 4 bone fusion.

SUMMARY

Therefore, what is needed is a simplified method of capitolunate fusionwhich improves the fusion potential by providing consistent compressionof the capitate and lunate bones along an axis generally perpendicularto the fusion plane. The present invention provides such solution byproviding an improved method and device for isolated 2 bone fusion ofthe capitate and lunate by a capitate cutting block and a capitolunateplate. For 3 and 4 bone fusion, the block is extended to acapitate-hamate cutting block and two additional variations of the plateallow for additional screw purchase into the hamate (3 and 4 bonefusion) or into hamate and triquetrum (4 bone fusion).

The capitate cutting block is designed to aid the surgeon inreproducibly being able to remove the exact right amount of bonematerial from the capitate bone and lunate bone (if needed) to allowproper fitting and alignment of the capitolunate fusion plate. Thepresent invention allows the screw or screws to be inserted in a nearperpendicular alignment to the fusion plane of co-linear bones. Thepresent invention makes use of a cutting block that allows one to removea wedge of bone in the capitate bone in a precise reproducible manner.The wedge created not only accurately matches the fusion plate butallows screw(s) to placed so that there are more perpendicular to thefusion plane. A variation of the capitate cutting block may include asemi-circular metal extension that would allow for the block to moresecurely and reproducibly rest on the capitate. The extension wouldmirror the circular shape of the proximal aspect of the capitate.

The capitate-hamate cutting block is similar to the capitate-lunatecutting block but it extends ulnarly and aids in removing a wedge of thehamate as well. A variation of this block would also include a metalextension proximally that would mirror the circular shape of theproximal capitate and possibly the proximal hamate.

The capitolunate plate is ideally suited to fuse the capitate and lunatecarpal bones. In the preferred method, two holes are designed to captureand insert from the capitate to the lunate. These holes are angled toallow the screws to be more perpendicular to the fusion. These holesallow for locking or non-locking screws. They can also be variablyangled. The screws can be locking, non-locking, fully, or partiallythreaded. The preferred method is to use non-locking partially threadedscrews placed in a slightly angled position by using an angled drillguide. The distal part of the plate sits on the dorsal wedge on thecapitate and a set of holes for screws also. These holes are angledslightly distally and allow for locking or non-locking screws. They canalso be variably angled. The screws can be locking, non-locking, fully,or partially threaded.

The capito-hamate-lunate plate is ideally suited to fuse the capitate,hamate, and lunate carpal bones. In the preferred method, one hole isdesigned to capture and insert from the capitate to the lunate and onehole is designed to capture and insert from the hamate to the lunate.These holes are angled to allow the screws to be more perpendicular tothe fusion plane. These holes allow for locking or non-locking screws.They can also be variable angled. The screws can be locking,non-locking, fully, or partially threaded. The preferred method is touse non-locking partially threaded screws placed in the slightly angledposition by using an angled drill guide. The distal part of the platerests on the capitate and hamate. In the preferred method, there wouldbe two set of variably angled locking holes that allow purchase into thecapitate and hamate.

The capito-hamate-lunato-triquetrum plate is ideally suited to fuse thecapitate, hamate, lunate, and triquetrum carpal bones. In the preferredmethod, two holes are designed to capture and insert from capitate tolunate and two holes are designed to capture and insert from the hamateand triquetrum. One variation of the plate would only have one hole fromthe capitate to the lunate. Another variation would only have one holdfrom the hamate to the triquetrum. The distal part of the plate wouldrest on the capitate and hamate. In the preferred method, there would betwo set of variably angled locking holes that allow purchase into thecapitate and hamate.

The present invention provides a fixation plate kit for bone fusions ina wrist. The kit includes a cutting block and a fixation plate. Thecutting block has at least one hole for temporarily securing the cuttingblock to a capitate bone and a plurality of cutting slits for providingaccess to the capitate bone and other wrist bones for cutting into thebones. The cutting block has a first portion and a second portion whereat least one opening is present in the first portion allowing thecutting to create a first surface or plane on the capitate bone, Thecutting block second portion has a second slit or opening allowing thesurgeon to cut the bone and create a second surface or plane on thecapitate or additional and alternative bones in the wrist. The firstsurface and second surface are angled away from each other in agenerally perpendicular direction, although the angle could be acute orobtuse.

The cutting block is configured to allow the surgeon to cut the boneaway in the capitate and other appropriate bones to allow for the kit'sfixation plate. The fixation plate comprises an elongated plate having afirst end and a second end. The first end having a first surface with atleast one hole for securing the fixation plate to the capitate bone; andthe second end having a second surface extending from the first surface,at a transition point, and forming an angle with the first surface;wherein the second surface has at least one hole through the second endfor securing the second end of the fixation plate to at least oneadditional bone. The fixation plate first surface is generalperpendicular to the second surface although the angle could be acute orobtuse. The fixation plate is ideally a capitolunate plate. The platecan be configured for a two-bone fusion, three-bone fusion, or four-bonefusion.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be better understood on reading the followingdetailed description of non-limiting embodiments thereof, and onexamining the accompanying drawings, in which:

FIG. 1 is a detail view of the bones of he hand and wrist forexplanatory purposes;

FIG. 2A is an image of a wrist with a circular 4 corner plate fixed tothe wrist bones;

FIG. 2B is an image of a wrist with a 4 corner fusion using staples;

FIG. 3A is an image of a wrist after a capitolunate fusion using screwsin an antegrade fashion;

FIG. 3B is an image of a wrist after a capitolunate fusion using screwsin a retrograde fashion;

FIG. 4A is a radiographic image showing a profile view of perspectiveview of a human wrist;

FIG. 4B is the same radiographic image with the capitate and lunateoutlined in black;

FIG. 5A is an x-ray image of a human wrist showing the cutting block ofthe present invention aligned along the capitate and lunate bones;

FIG. 5B is an example of variation of the cutting block with a curvedextension that would rest under the proximal capitate;

FIG. 5C is a top view of the cutting block of the present invention;

FIG. 5D is radiographic view of wedge cut that would be created afterusing the cutting block;

FIG. 6A is a top view of the capitolunate fusion plate of the presentinvention;

FIG. 6B is a top view of an additional embodiment of a capitolunatefusion plate of the present invention;

FIG. 6C is the side view of the capitolunate fusion plate of the presentinvention;

FIG. 7 is a top perspective view of an illustrative example of amulti-bone wrist cutting block in accordance with the present invention;

FIG. 8A is a top perspective view of one example of a generic three-bonecarpal fusion plate in accordance with the present invention;

FIG. 8B is a top perspective view of one example of a generic four-bonecarpal fusion plate in accordance with the present invention;

FIG. 9A is a side view of an additional embodiment of the fixation platefixed to one or more bones in a wrist in accordance with the presentinvention; and

FIG. 9B is a top perspective view an additional embodiment of thefixation plate fixed to one or more bones in a wrist in accordance withthe present invention.

DETAILED DESCRIPTION

The present invention, as seen in FIGS. 5A-8B, provides various cuttingblocks and bone fusion plates ideally suited for the wrist and wristbones.

As seen in FIGS. 5A-5C, the present invention provides a cutting block51, 52 designed to create a wedge cut (see FIG. 5D) into the capitatebone. The cutting block 51, 52 has a curvature or concave portion on thebottom surface or bone mating side (as seen in FIG. 5A and 5B)configured to mate with the capitate bone or curved to mate with thecurvature of the capitate bone. The curvature allows the cutting block51,52 to securely rest on top of the capitate bone and holds the cuttingblock 51, 52 in place before it is secured (i.e. with K-wires). Thecutting block 51, 52 may also be designed for the surgeon to cut asection of bone on the lunate bone. The cutting block 52 (FIG. 5B) is avariation of the cutting block 51 (FIG. 5A) where there is proximalcurved extension 54 that allows the block 52 to tightly rest under thehead of the capitate. The cutting block 52 with the curved extension 54allows a more secure and reproducible fit of the cutting block 52 ontoto the capitate.

The cutting block 51, 52 has one or more holes 53 for K-wires to securethe block to the capitate bone. The cutting block 51, 52 also has slits55, 56, and 57 designed for receiving the saw blade (not shown) used tomake the cuts into the capitate and possibly the lunate if needed. Thesuperior part of the block 51, 52 compared to the inferior part may havevarying heights allowing for varied depth of cut into the bone.Additional control of the depth is possible by etching the saw with alimiter line, or by welding a limiter block on the saw. In a preferredembodiment, the superior slit 57 is roughly 90 degrees out of the planewith the inferior slit 56. The design provides an end result with awedge cut into the capitate in a general 90-degree angle allowing theplate to sit deep within the capitate so as to prevent dorsalimpingement of the plate and the dorsal distal radius. The cutting block51, 52 may also be designed to have fewer slits or more slits; or with adifferent mechanism such as a resting shelf to help guide the saw. Theslits 55, 56, 57 are for use with the cutting saw and may be angledslits. There may be more than one slit 55 connecting or extending thesuperior slit 57 and inferior slit 56. Further, slit 55 may be a seriesof one or more slits or openings with varying depths or angles. Inaddition, the cutting block may be configured to work with standardsquare end cutting blades or angled blades, which might match thedesired angle of the two surfaces created by the cuts from the inferioror superior slits 56, 57.

The cutting block 51, 52 may also incorporate one or more lines to markwhen or where to stop cutting. The cutting block 51, 52 may be providedin different sizes such as small, medium, and large. Further, thecutting block 51, 52 is designed, so that once the bone material andcutting block are removed the opening from the cut fits the capitolunateplate (the “CL Plate”) including the angle a of the CL Plate 61 (seeFIG. 6C).

The cutting block 51, 52 is designed to create an opening FIG. 5D to fita capitolunate (CL) Plate. The generic version of the CL Plate 61 isseen in FIG. 6A. An additional embodiment of the butterfly CL Plate 62,is seen in FIG. 6B which has rounded edges at the corners. The roundededges could allow the plate 62 to sit deeper within the wedge cut, beless prominent dorsally, and cause less chance of dorsal impingement.Other versions of a CL Plate are also possible which may have lesscurvature at the edges or may be narrower at one end (ulnarly). In bothversions, the CL Plate 61, 62 has an upper portion 63 which sits on thedistal dorsal capitate bone and a lower portion 67 which rest in thewedge created in the proximal capitate. The CL Plate 61 has one or moreupper holes 68 allowing the upper portion 63 of the CL Plate 61 to befixed or attached to the capitate bone. The CL Plate 61, 62 has one ormore lower holes 69 allowing the lower portion 67 of the CL Plate 61, 62to be attached to the lunate bone but also partly go through theproximal part of the capitate. The upper portion 63 and lower portion 67of the CL Plate 61, 62 are connected but set an angle a which isgenerally 90 degrees, see FIG. 6C. However, the angle a need not be 90degrees.

The CL Plate 61, 62 is angled so that the screw(s) that are placedacross the fusion plane or joint are nearly perpendicular. Perpendicularcompression is preferred as it is known to increase fusion rates anddecrease the time to fusion. In order to achieve even a better angle toget perpendicular, the screws themselves can be variably angled so thatthey are not completely perpendicular to the plate. Variably angledscrew fixation is a common technique used in orthopaedics.

In a preferred embodiment, the CL Plate would use two 2.3 mm screws toattach the upper portion 63 to the capitate bone and two 2.3 mm screwsto attach the lower portion 67 to the lunate bone. The screws may belocking and may also be partially threaded with non-locking threaded lagscrews. They can be fixed or variably angled.

As seen in FIGS. 6A and 6B, the CL Plate 61, 62 would be fixed to thewrist allowing the upper portion 63 to be fixed to the capitate bone andin conjunction with the lower portion 67 allows for screw fixationacross the fusion plane. The plate 61, 62 transition point 65 from theupper portion 63 to the lower portion 67 and is also where the bend inthe plate is with an angle a.

An alternative embodiment of the preferred invention is shown in FIGS.7-8B, which displays a cutting block 71 (FIG. 7) and plates (FIGS.8A-8B) for a three and four bone fusion. FIG. 7 shows a superior view ofthe cutting block 81 for a 3 or 4 bone fusion which is designed tocreate an opening to fit the plate 81, 82 as seen in FIG. 8A and 8B.This block 71 makes a wedge cut within the capitate and hamate carpalbones. The block may also an inferior curve metal extension that wouldsit in the midcarpal space underneath the capitate and hamate articularsurfaces allowing more resting stability. The 3-bone plate 81 (FIG. 8A)has an upper portion 83 for mating with the capitate bone and the hamatebone through use of the upper holes 88. The plate 81 has a lower portion87 for mating with the lunate bone through use of the lower holes 89 andthe use of screws as previously described. The 4-bone plate 82 (FIG. 8B)has an upper portion 83 for mating with the capitate bone and the hamatebone through use of the upper holes 88. The plate 82 has a lower portion87 for mating with the lunate bone and the triquetrum bone through useof the lower holes 89 and the use of screws as previously described.Further embodiments of the Plate 81, 82 may include rounded corners,narrower proximally than distally, and/or curved edges.

The upper portion 83 and lower portion 87 of the plate 81, 82 areconnected with a bend at 85 but set at an angle a which is generally 90degrees. However, the angle a need not be 90 degrees. However, agenerally perpendicular compression at the fusion plate is ideal. Forthe three bone plate 81, the lower portion 87 of the plate 81 isproximate to and designed so that the screws can be placed nearlyperpendicular to the fusion plane between the capitate and lunate. Forthe four bone plate 82, the lower portion 87 of the plate 82 isproximate to and designed so that radial screws can be placed nearlyperpendicular to the fusion plane between the capitate and lunate andulnar screws can be placed nearly perpendicular to the fusion planebetween the hamate and triquetrum. Because of the asymmetric nature ofthe capitate and hamate and the rest of the carpal bones, there may be aneed for cuttings blocks and plates designated for the right and leftsides when performing three and four bone fusions.

In use, the surgeon installs the cutting block 51 to the patient'scapitate bone using K-wires. The surgeon then cuts the bone from thecapitate bone (in a 2-bone fusion) to conform within the design of thecutting block 51 to provide a wedge cut into the capitate bone. Thefirst and second plane in a generally perpendicular orientation to eachother using slits 56 and 57. Next, the surgeon uses a saw through thetwo parallel slits 55 to complete the wedge resection. The surgeon thenremoves the K-wires and block from the capitate. Small osteotomes canthen be used to help remove the wedge of bone from the capitate. Thesurgeon then reduces the capitate and lunate in the most appropriateposition which is co-linear in most cases. K-wires can be used totemporarily hold this position. The surgeon then installs the fusionPlate 61, 62 and inserts one or more screws into the capitate bonethrough the top fusion plate hole(s) 68. Next, the Next the surgeoninstalls one or more screws into the lunate bone through the bottomfusion plate hole(s) 69 forming a generally perpendicular fixation andcompression between the capitate and lunate bones allowing for maximumfusion success. Alternatively, the surgeon could install the plate 61,62and place screw(s) into the lunate bone first and then the capitatebone.

An additional embodiment is depicted in FIGS. 9A and 9B which illustratea side and top perspective view of a fixation plate fixed to one or morebones in a wrist. The fixation plate 90 mechanism includes the fixationplate having a first end 97 and a second end 92. The first end 97 isaffixed to the capitate bone by two screws or other attachment devicesand described herein 98, 99. The second end 92 is affixed to one or moreother bones in the wrist by bone by two screws or other attachmentdevices and described herein 93, 94. In this embodiment, the first endhas two openings which are perpendicular to the longitudinal directionof the fixation plate and are configured to receive the two screws 98,99. The second end has two openings which run along the axis of thefixation plate and are configured to receive the other two screws 93,94.

Further, the first end 97 has its top surface which is generallyperpendicular to the top surface of the second end 92. The two surfacesmeet or extend from the transition point 95. Through this fixation plateand generally perpendicular or angled two surface configuration, thebones in the wrist can be fixed to the plate and aligned allowing forimproved or proper fusion.

It will be understood that various details of the present subject mattermay be changed without departing from the scope of the subject matter.Furthermore, the foregoing description is for the purpose ofillustration only, and not for the purpose of limitation.

We claim:
 1. A cutting block for bone fusions comprising: a bone matingsurface, wherein the bone mating surface has a concave portionconfigured to mate with a capitate bone; a cutting side. wherein thecutting side has an opening configured to provide access to at least onebone for cutting; at least one hole, wherein the at least one hole isconfigured to secure the cutting block to the capitate bone; a pluralityof slits, wherein the plurality of slits are configured to provideaccess to the capitate bone and at least one additional wrist bone forcutting into the capitate bone or at least one additional wrist bone;wherein the cutting block has a first planar portion and a second planarportion; wherein a first slit in the first planar portion is configuredto provide access to create a first plane on the capitate bone; andwherein a second slit in the second planar portion is configured toprovide access to create a second plane on at least one additional bone.2. The cutting block of claim 1, wherein the cutting block has a curvedextension protruding from a lower surface of one end of the block,wherein the curved extension is configured to receive a head of thecapitate bone.